Display device integrated with touch screen panel and method for fabricating the same

ABSTRACT

Disclosed is a display device integrated with a touch screen panel and a method for fabricating the same. The display includes: a TFT positioned at each pixel region; a first electrode spaced from one of a source electrode or a drain electrode of the TFT; a second electrode facing the first electrode; a TFT protective layer positioned on the TFT and has a first contact hole; a touch signal line positioned between a first touch connection pattern, which is made of the same material as the first electrode, and a second touch connection pattern made of the same material as the second electrode, and transfers a touch driving signal to the second touch connection pattern; a first connection pattern made of the same material as the second electrode; and a first electrode protective layer positioned on the first electrode and the touch signal line.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional application of U.S. patent applicationSer. No. 14/540,528 filed Nov. 13, 2014, which claims priority from andthe benefit under 35 U.S.C. §119(a) of Korean Patent Application No.10-2014-0077034, filed on Jun. 24, 2014, both of which are herebyincorporated by reference for all purposes as if fully set forth herein.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a display device integrated with atouch screen panel and a method for fabricating the same.

Description of the Prior Art

As an information-based society has continued to develop, the demand fordisplay devices for displaying images in various forms is increasing.Recently, Liquid Crystal Displays (LCD), Plasma Display Panels (PDP) andOrganic Light Emitting Diode (OLED) Display Devices are utilized fordisplaying the images.

Such display devices provide an input means based on touches that aredifferent from the typical input means, such as buttons, keyboards andmouses, which enables a user to conveniently and intuitively input dataor commands.

In order to provide such an input means based on touches, it is requiredto recognize a user's touch and accurately detect a touch coordinate.

In doing so, typically, a touch sensing technique adopting one of aresistive type, a capacitive type, an electromagnetic resonance type, aninfrared type and acoustic wave type is provided.

In addition, a touch sensor that is built in the display device has beendeveloped in applying a touch screen to the display device.Particularly, the display device of an in-cell type in which a commonelectrode formed on a lower substrate is utilized for a touch sensingelectrode has been developed. However, since the display device of thein-cell type requires an additional process in order to form the touchsensing electrode, it takes a high cost and a long time to manufacturethe product, which makes the product uncompetitive.

SUMMARY OF THE INVENTION

In this background, the present invention is to provide a display deviceintegrated with a touch screen panel and a method for fabricating thesame, by which the manufacturing process may be simplified.

In accordance with an aspect of the present invention, a display devicemay include: a gate line that is positioned in the first direction onthe substrate to transfer a gate signal; a data line that is positionedin the second direction on the substrate to transfer a data signal; athin film transistor that is positioned at each pixel defined by theintersection of the gate line and the data line; a first electrode thatis spaced from one of a source electrode or a drain electrode of thethin film transistor; a second electrode that faces the first electrode;a thin film transistor protective layer that is positioned on the thinfilm transistor and has a first contact hole formed therein; a touchsignal line that is positioned between a first touch connection pattern,which is made of the same material as that of the first electrode to beseparated from the first electrode, and a second touch connectionpattern, which is made of the same material as that of the secondelectrode to be connected with the second electrode, and transfers atouch driving signal to the second touch connection pattern; a firstconnection pattern that is made of the same material as that of thesecond electrode and connects the source electrode or the drainelectrode with the first electrode through the first contact hole; and afirst electrode protective layer that is positioned on the firstelectrode and the touch signal line.

In accordance with another aspect of the present invention, a displaydevice may include: a display panel that includes; a thin filmtransistor that is positioned at each of N×P pixels defined byintersections of gate lines, which are positioned in the first directionon a substrate to transfer gate signals, and data lines, which arepositioned in the second direction on the substrate to transfer datasignals, N×P first electrodes that are spaced from one of sourceelectrode or drain electrode of the thin film transistor, P secondelectrodes that face the first electrodes and provide the same signal toall of the N pixels, a thin film transistor protective layer that ispositioned on the thin film transistor and has a first contact holeformed therein, a touch signal line that is positioned between a firsttouch connection pattern, which is made of the same material as that ofthe first electrode to be separated from the first electrode, and asecond touch connection pattern, which is made of the same material asthat of the second electrode to be connected with the second electrode,and transfers a touch driving signal to the second touch connectionpattern, N×P first connection patterns that are made of the samematerial as that of the second electrode and connect one of the sourceelectrode and the drain electrode with the first electrode through thefirst contact hole, and a first electrode protective layer that ispositioned on the first electrode and the touch signal line; a touchintegrated circuit that applies a touch driving signal to all or some ofa plurality of the second electrodes when the display panel operates ina touch driving mode; a data driving unit that supplies a data voltageto a plurality of the data lines when the display panel operates in adisplay driving mode; and a gate driving unit that supplies scan signalsto a plurality of the gate lines in sequence when the display paneloperates in a display driving mode.

In accordance with another aspect of the present invention, a method forfabricating signal lines of a display device integrated with a touchscreen panel may include: forming a thin film transistor on a substrate;accumulating a thin film transistor protective layer covering the thinfilm transistor, a first electrode layer and a conductive metal layer;etching the first electrode layer, the conductive metal layer and thethin film transistor protective layer by using a first photo-mask toform a first contact hole, through which a source electrode or a drainelectrode is exposed, in the first electrode layer and the thin filmtransistor protective layer, and forming a first electrode and a touchsignal line; coating a first electrode protective layer; coatingphotoresist by using a second photo-mask and forming a first electrodeand a first touch connection pattern separated from the first electrode;and forming a second electrode and a second touch connection patternmade of the same material as that of the second electrode to beconnected with the second electrode by using a third photo-mask, and atthe same time, forming a first connection pattern, which connects one ofthe exposed source electrode or the drain electrode with the firstelectrode through the first contact hole.

According to the present invention, it may be provided a method forfabricating a display device integrated with a touch screen panel bywhich the manufacturing process can be simplified, and a display devicefabricated by the method.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the presentinvention will be more apparent from the following detailed descriptiontaken in conjunction with the accompanying drawings, in which:

FIG. 1 schematically illustrates a display device integrated with atouch screen panel according to an embodiment of the present invention;

FIG. 2 illustrates capacitance components (Cself, Cpara1 and Cpara2)generated in a touch driving mode in a display device integrated with atouch screen panel according to an embodiment of the present invention;

FIG. 3 is a plan view of a panel included in a display device integratedwith a touch screen panel according to an embodiment of the presentinvention;

FIG. 4 illustrates an example of a sectional view of a panel in a casewhere a display device integrated with a touch screen panel is a liquiddisplay device according to an embodiment of the present invention;

FIG. 5 is another plan view of a panel included in a display deviceintegrated with a touch screen panel according to an embodiment of thepresent invention;

FIG. 6 is a diagram illustrating processes of manufacturing a thin filmtransistor on a substrate;

FIG. 7 is a diagram illustrating examples of processes according to thepresent invention;

FIGS. 8A and 8B are sectional views illustrating configurations of apixel portion, a gate pad portion and a data pad portion of a displaydevice according to an embodiment of the present invention;

FIGS. 9A to 9E are plan views illustrating configurations of a pixelportion, a gate pad portion and a data pad portion of a display deviceaccording to an embodiment of the present invention;

FIG. 10 is a sectional view illustrating a configuration of a displaydevice according to an embodiment of the present invention;

FIG. 11 illustrates accumulation of a thin film transistor, the firstprotective layer, a thin film transistor protective layer and the firstelectrode;

FIGS. 12A to 12F illustrate a process of forming the first electrode, atouch signal line and a thin film transistor protective layer accordingto the first embodiment of the present invention;

FIGS. 13A to 13E illustrate a process of forming the first electrodeprotective layer and the second electrode according to the firstembodiment of the present invention;

FIGS. 14A to 14F illustrate a process of forming the first electrode, atouch signal line, a thin film transistor protective layer according tothe second embodiment of the present invention;

FIGS. 15A to 15E illustrate a process of forming the first electrodeprotective layer and the second electrode according to the secondembodiment of the present invention;

FIGS. 16 and 17 are flowcharts illustrating a process of forming signallines of a display device in which a touch sensor is built according toan embodiment of the present invention;

FIG. 18 illustrates an embodiment of the present invention in a casewhere an activation layer of a thin film transistor is a metal oxidesemiconductor; and

FIG. 19 illustrates an embodiment of the present invention in a casewhere an activation layer of a thin film transistor is low temperaturepoly silicon.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Hereinafter, embodiments of the present invention will be described withreference to the accompanying drawings. In the following description,the same elements will be designated by the same reference numeralsalthough they are shown in different drawings. Further, in the followingdescription of the present invention, a detailed description of knownfunctions and configurations incorporated herein will be omitted when itmay make the subject matter of the present invention rather unclear.

In addition, terms, such as first, second, A, B, (a), (b) or the likemay be used herein when describing components of the present invention.Each of these terminologies is not used to define an essence, order orsequence of a corresponding component but used merely to distinguish thecorresponding component from other component(s). In the case that it isdescribed that a certain structural element “is connected to”, “iscoupled to”, or “is in contact with” another structural element, itshould be interpreted that another structural element may “be connectedto”, “be coupled to”, or “be in contact with” the structural elements aswell as that the certain structural element is directly connected to oris in direct contact with another structural element.

The present invention provides a processing method of using metalsubstances necessary for the formation of a common electrode and/ormetal substances necessary for the formation of a touch signal line inorder to connect a pixel electrode with a source electrode or a drainelectrode, and a display device that includes a connection pattern bywhich a source electrode or a drain electrode is connected with a pixelelectrode.

FIG. 1 schematically illustrates a display device integrated with atouch screen panel according to an embodiment of the present invention.

Referring to FIG. 1, the display device 100 integrated with a touchscreen panel according to an embodiment of the present inventionincludes a panel 110, a data driving unit 120, a gate driving unit 130and an integrated circuit 140 (hereinafter, referred to as a “touchintegrated circuit”) for controlling a touch signal, or the like.

On the panel 110, a plurality of gate lines GL are formed in the firstdirection (e.g., lateral direction or longitudinal direction), and aplurality of data lines DL are formed in the second direction (e.g.,longitudinal direction or the lateral direction). Also, a plurality ofpixels P are defined at each crossing of the data lines DL and the gatelines GL.

In a pixel area of each pixel P, a source electrode or a drain electrodeis connected with the data line DL, and a gate electrode is connectedwith the gate line GL. Further, one of the drain electrode and thesource electrode is connected with a pixel electrode (or the firstelectrode).

In addition, a plurality of electrodes S11 to S14, S21 to S24 and S31 toS34, which are grouped or blocked by a plurality of electrode groups, isformed to be spaced from each other on the panel 110.

The panel 110 plays the role of a “touch screen panel (TSP)” as well asa “display panel”.

That is, the panel 110 may be a combined panel of the display panel andthe touch screen panel, or may be a display panel of an in-cell type inwhich the touch screen panel (TSP) is built.

When the panel 110 plays the role of the display panel, the panel 110 isdriven in a “display driving mode”, and when the panel 110 plays therole of the touch screen panel, the panel 110 is driven in a “touchdriving mode”.

In the display driving mode of the panel 110, the data driving portion120 supplies a data voltage Vdata or a data signal for a display to theplurality of data lines DL.

In the display driving mode of the panel 110, the gate driving portion130 supplies a gate signal or a scan signal for a display to theplurality of gate lines GL in sequence.

The touch integrated circuit 140 applies touch driving signals to all orsome of the plurality of electrodes S11 to S14, S21 to S24 and S31 toS34 directly connected through touch signal lines in the touch drivingmode of the panel 110. Here, the touch driving signal may be referred toas a touch sensing signal, a touch sensing voltage or a touch drivingvoltage as well.

For example, in the touch driving mode of the panel 110, the touchintegrated circuit 140 applies touch driving signals to all or some of aplurality of electrode groups which are grouped by the plurality ofelectrodes S11 to S14, S21 to S24 and S31 to S34.

Meanwhile, the display device 100 integrated with a touch screen panel,according to an embodiment of the present invention, may further includea timing controller (not shown) for controlling the driving timing ofthe data driving portion 120 and the gate driving portion 130.

In addition, the display device 100 integrated with a touch screenpanel, according to an embodiment of the present invention, may furtherinclude a touch controller (not shown) that receives sensed data (e.g.,capacitance, the change in capacitance, voltages, or the like) measuredby the touch integrated circuit 140 through the plurality of electrodesS11 to S14, S21 to S24 and S31 to S34 that play the role of touchelectrodes, and detects a touch and a coordinate thereof.

Meanwhile, the display device 100 integrated with a touch screen panel,according to an embodiment of the present invention, repeats operationsof the display driving mode and the touch driving mode. Further, thetiming of the display driving mode and the touch driving mode may becontrolled by control signals output from the timing controller or thetouch controller, or may be controlled by cooperation of the timingcontroller and the touch controller in some cases.

Meanwhile, the display device 100 integrated with a touch screen panel,according to an embodiment of the present invention, adopts acapacitance touch type by which the touches and coordinates are detectedbased on the change in capacitance through a plurality of touchelectrodes (e.g., lateral electrodes and longitudinal electrodes) formedon the touch screen panel.

The capacitance touch type may be divided into a mutual capacitancetouch type and a self-capacitance touch type.

In the mutual capacitance touch type, one of the capacitance touchtypes, one of the lateral electrodes and the longitudinal electrodes maybe Tx electrodes (driving electrodes) which are applied with a drivingvoltage, and the other of the lateral electrodes and the longitudinalelectrodes may be Rx electrodes (sensing electrodes) that sense thedriving voltage to make a capacitor with the Tx electrodes. The mutualcapacitance touch type detects the touches and the touch coordinates,based on the change in capacitance (mutual capacitance) between the Txelectrodes and the Rx electrodes according to the touches of pointers,such as fingers, pens, or the like.

In the self-capacitance touch type, another of the capacitance touchtypes, each touch electrode makes capacitance (self-capacitance) withthe pointers, such as fingers, pens, or the like. Further, theself-capacitance touch type measures a capacitance value between thetouch electrode and the pointer according to the touch of the pointer tothereby detect the touch and the touch coordinate. In theself-capacitance touch type, the driving voltage (touch driving signal)is applied and sensed through the touch electrode, differently from themutual capacitance touch type. Accordingly, the Tx electrodes are notdistinguished from the Rx electrodes in the self-capacitance touch type.

The display device 100 integrated with a touch screen panel according toan embodiment of the present invention may adopt one of theabove-described capacitance touch types (i.e., mutual capacitance touchtype and self-capacitance touch type). For the convenience ofexplanation, the embodiments adopting the self-capacitance touch typewill be described in the present specification.

The data driving portion 120 may include at least one data driverintegrated circuit (IC) (also, referred to as a “source driverintegrated circuit”). The data driver integrated circuit may be mountedon a bonding pad of the panel 110 in the type of tape automated boding(TAB) or chip-on-glass (COG), or may be directly formed on the panel110. In some cases, the data driver integrated circuit may beintegratedly formed on the panel 110.

The gate driving portion 130 may be positioned at one side of the panel110 as shown in FIG. 1, or at both sides thereof, according to thedriving type.

In addition, the gate driving portion 130 may include at least one gatedriver integrated circuit (IC). The gate driver integrated circuit maybe mounted on a bonding pad of the panel 110 in the type of tapeautomated boding (TAB) or chip-on-glass (COG), or may be directly formedon the panel 110 in a gate-in-panel (GIP) type. In some cases, the gatedriver integrated circuit may be integratedly formed on the panel 110.

The touch integrated circuit 140 is an element separated from the datadriving portion 120 and the gate driving portion 130 as shown in FIG. 1.The touch integrated circuit 140 may be provided at the outside of thedata driving portion 120 and the gate driving portion 130, or may beprovided inside the separate driver IC (e.g., display driver IC) thatmay include at least one of the data driving portion 120 and the gatedriving portion 130, according to the implementation. Alternatively, thetouch integrated circuit 140 may be implemented as an internal elementof the data driving portion 120 and the gate driving portion 130.

Accordingly, the operation by which the touch integrated circuit 140applies the touch driving signal to all or some of the plurality ofelectrodes acting as touch electrodes in the touch driving mode maycorrespond to the operation by which the separate driver IC includingthe touch integrated circuit 140 applies the touch driving signal to allor some of the plurality of electrodes acting as touch electrodes, ormay correspond to the operation by which the data driving portion 120 orthe gate driving portion 130 including the touch integrated circuit 140applies the touch driving signal to all or some of the plurality ofelectrodes acting as touch electrodes, according to design.

The touch integrated circuit 140 is not limited to the detailedimplementation and designs thereof, but it may be any element itself oran internal or external element thereof as long as it has the same orsimilar function as or to that set forth in the present specification.

In addition, although FIG. 1 illustrates only one touch integratedcircuit 140, two or more touch integrated circuits may be provided.

Meanwhile, additional signal lines, which are connected with each of theplurality of electrodes S11 to S14, S21 to S24 and S31 to S34, arerequired to allow the touch integrated circuit 140 to apply the touchdriving signal to all or some of the plurality of electrodes S11 to S14,S21 to S24 and S31 to S34.

At least one signal line, which is connected with each of the pluralityof electrodes S11 to S14, S21 to S24 and S31 to S34 to transfer thetouch driving signal or a common voltage, may be formed on the panel 110in the first direction (e.g., longitudinal direction) or in the seconddirection (e.g., lateral direction).

Two or more signal lines, which are connected with each of the pluralityof electrodes S11 to S14, S21 to S24 and S31 to S34, may give an effectthat the resistance may be reduced.

Meanwhile, the formation direction of at least one signal line, which isconnected with each of the plurality of electrodes S11 to S14, S21 toS24 and S31 to S34, may vary according to whether the plurality ofelectrodes S11 to S14, S21 to S24 and S31 to S34 is grouped and sensedin the first direction (e.g., longitudinal direction) in which the datalines are formed, or whether the plurality of electrodes S11 to S14, S21to S24 and S31 to S34 is grouped and sensed in the second direction(e.g., lateral direction) in which the gate lines are formed.

If the plurality of electrodes S11 to S14, S21 to S24 and S31 to S34 isgrouped and sensed in the first direction (e.g., longitudinal direction)in which the data lines are formed, at least one signal line, which isconnected with each of the plurality of electrodes S11 to S14, S21 toS24 and S31 to S34, may be formed in the first direction (e.g.,longitudinal direction) in which the data lines are formed (see FIG. 3).

If the plurality of electrodes S11 to S14, S21 to S24 and S31 to S34 isgrouped and sensed in the second direction (e.g., lateral direction) inwhich the gate lines are formed, at least one signal line, which isconnected with each of the plurality of electrodes S11 to S14, S21 toS24 and S31 to S34, may be formed in the second direction (e.g., lateraldirection) in which the gate lines are formed.

In the present specification, the plurality of electrodes S11 to S14,S21 to S24 and S31 to S34 acts as “touch electrode” to which the touchdriving signals are applied all or in part in the touch driving mode,and acts as “common electrodes” that face the pixel electrodes on thepanel to be thereby applied with a common voltage Vcom in the displaydriving mode, as set forth above. The electrode that acts as the touchelectrode or the common electrode according to the driving mode isreferred to as the second electrode.

The display device 100 integrated with a touch screen panel, accordingto an embodiment of the present invention, may be a liquid crystaldisplay device of an in-plane-switching (IPS) type, in which liquidmolecules horizontally positioned are rotated to display images so thathigh resolution, low power consumption and a wide viewing angle may beobtained. More specifically, the display device 100 may be the displaydevice of an advanced high performance IPS (AH-IPS) type.

In this case, the pixel electrodes and the common electrodes S11 to S14,S21 to S24 and S31 to S34 may be formed on the same substrate in orderto generate a horizontal electric field between the pixel electrodes andthe common electrodes S11 to S14, S21 to S24 and S31 to S34 in thedisplay driving mode.

The display device 100 integrated with a touch screen panel, accordingto another embodiment of the present invention, may be an organic lightemitting display device in which an organic light-emitting layer isformed between the pixel electrode and the common electrode. At thistime, the pixel electrode and the common electrode may be formed on thesame substrate.

FIG. 2 illustrates capacitance components (Cself, Cpara1 and Cpara2)generated in a touch driving mode in a display device integrated with atouch screen panel according to an embodiment of the present invention.

Referring to FIG. 2, the plurality of electrodes S11 to S14, S21 to S24and S31 to S34, which acts as the touch electrodes in the touch drivingmode and acts as the common electrodes that form a liquid capacitor withthe pixel electrode in the display driving mode, createsself-capacitance Cself with pointers, such as fingers, pens, or the likein order to detect the touch and the touch coordinate in the touchdriving mode. Meanwhile, the plurality of electrodes acting as thecommon electrodes may create parasitic capacitance Cpara1 and Cpara2with the gate lines and the data lines, but the parasitic capacitance istoo small to be considered.

Hereinafter, the panel 110 included in the display device 100 integratedwith a touch screen panel according to an embodiment of the presentinvention, supply the common voltage and the touch driving signal to theplurality of electrodes S11 to S14, S21 to S24 and S31 to S34 acting asthe common electrodes or the touch electrodes, supply the data voltageand the touch driving signal (or an equivalent signal) to the data linesDL, and supply data voltage and the touch driving signal (or anequivalent signal) to the gate lines GL will be described in detail.

The panel 110 of the display device 100 integrated with a touch screenpanel according to an embodiment of the present invention may bedescribed in detail with reference to FIGS. 3 to 5.

FIG. 3 is a plan view of a panel included in a display device integratedwith a touch screen panel according to an embodiment of the presentinvention.

Referring to FIG. 3, the panel 110 is formed with a plurality of datalines DL, a plurality of gate lines GL and a plurality of electrodes S11to S14, S21 to S24 and S31 to S34, as set forth above.

In addition, the panel 110 may operate in the display driving mode or inthe touch driving mode, as described above.

In this regard, the plurality of data lines DL and the plurality of gatelines GL, which are formed on the panel 110, allow the panel 110 tooperate as the display panel.

Further, the plurality of electrodes S11 to S14, S21 to S24 and S31 toS34 formed on the panel 110 allows the panel 110 to operate as both ofthe display panel and the touch screen panel.

More specifically, when the panel 110 operates as the display panel,i.e., when the panel 110 operates in the display driving mode, theplurality of electrodes S11 to S14, S21 to S24 and S31 to S34 is appliedwith the common voltage Vcom to be the “common electrodes” (or Vcomelectrodes) that face the pixel electrodes (the first electrodes, notshown).

Further, when the panel 110 operates as the touch screen panel, i.e.,when the panel 110 operates in the touch driving mode, the plurality ofelectrodes S11 to S14, S21 to S24 and S31 to S34 is applied with a touchdriving voltage to be the “touch electrodes” that form a capacitor withthe touch pointer (e.g., fingers, pens, or the like), so that thecapacitance of the capacitor is measured.

That is, the plurality of electrodes S11 to S14, S21 to S24 and S31 toS34 acts as the common electrodes (Vcom electrodes) in the displaydriving mode and acts as the touch electrodes in the touch driving mode.

Further, the common voltage Vcom is applied to the plurality ofelectrodes S11 to S14, S21 to S24 and S31 to S34 in the display drivingmode, and the touch driving signal is applied to the plurality ofelectrodes S11 to S14, S21 to S24 and S31 to S34 in the touch drivingmode, respectively.

In doing so, as shown in FIG. 3, signal lines SL11 to SL14, SL21 to SL24and SL31 to SL34 may be connected with the plurality of electrodes S11to S14, S21 to S24 and S31 to S34 in order to transfer the commonvoltage or the touch driving signal to the plurality of electrodes S11to S14, S21 to S24 and S31 to S34.

Accordingly, in the touch driving mode, the touch driving signal Vdtgenerated in the touch integrated circuit 140 may be transferred to allor some of the plurality of electrodes S11 to S14, S21 to S24 and S31 toS34 through the signal lines SL11 to SL14, SL21 to SL24 and SL31 toSL34. Also, in the display driving mode, the common voltage Vcomsupplied from a common voltage supplier (not shown) may be applied tothe plurality of electrodes S11 to S14, S21 to S24 and S31 to S34through the signal lines SL11 to SL14, SL21 to SL24 and SL31 to SL34.

Referring to FIG. 3, a pixel P is defined at each crossing of theplurality of the data lines DL and the plurality of the gate lines GL,which are formed on the panel 110. Here, each pixel may be one of a red(R) pixel, a green (G) pixel and a blue (B) pixel.

Referring to FIG. 3, two or more pixels may be defined on the area(hereinafter, referred to as a unit touch electrode area) where each ofthe plurality of electrodes S11 to S14, S21 to S24 and S31 to S34 actingas the common electrodes and the touch electrodes is formed. That is,one of the plurality of electrodes S11 to S14, S21 to S24 and S31 to S34may correspond to two or more pixels P.

For example, in one area (the unit touch electrode area) where each ofthe plurality of electrodes S11 to S14, S21 to S24 and S31 to S34 actingas the common electrodes and the touch electrodes is formed, 24×3 datalines DL and 24 gate lines GL may be disposed to define 24×3×24 pixelsP.

Meanwhile, each of the plurality of electrodes S11 to S14, S21 to S24and S31 to S34 acting as the common electrodes and the touch electrodesmay have a pattern of a block as shown in FIG. 3, or a pattern of a combin some cases.

Further, the present invention may be applied to a case where each ofthe plurality of electrodes S11 to S14, S21 to S24 and S31 to S34 actingas the common electrodes and the touch electrodes has a patternincluding a comb shape.

Although the plurality of electrodes S11 to S14, S21 to S24 and S31 toS34 acting as the common electrodes and the touch electrodes isillustrated to be twelve electrodes in a matrix of three rows and fourcolumns in the drawings of the present specification, this is just anexample for the convenience of explanation, and the plurality ofelectrodes acting as the common electrodes and the touch electrodes maybe formed by various numbers and in various matrix forms, consideringthe size of the display device 100 integrated with a touch screen paneland the panel 100, and design criteria of a touch system.

FIG. 4 illustrates an example of a sectional view of a panel in a casewhere a display device integrated with a touch screen panel is a liquiddisplay device according to an embodiment of the present invention.

FIG. 4 shows a sectional view of an area (the unit touch electrode area)where a single electrode among the plurality of electrodes S11 to S14,S21 to S24 and S31 to S34 acting as the common electrodes and the touchelectrodes is formed.

Referring to FIG. 4, on the panel 110 of the display device 100integrated with a touch screen panel according to an embodiment of thepresent invention, gate lines 402 are formed on a lower substrate 400 inthe first direction (in the lateral direction, i.e., to the left andright in FIG. 4), and a gate insulator 404 is formed thereon.

Data lines 406 are formed on the gate insulator 404 in the seconddirection (in the longitudinal direction, i.e., the directionperpendicular to the paper in FIG. 4), and the first protective layer408 is formed thereon.

A pixel electrode 410 and a signal line 412 of each pixel area may beformed on the first protective layer 408, and the second protectivelayer 414 may be formed thereon. Here, the signal line 412 leads fromeach of the plurality of electrodes S11 to S14, S21 to S24 and S31 toS34 acting as the common electrodes and the touch electrodes to thetouch integrated circuit 140 to transfer the common voltage Vcomgenerated in the common voltage supplier to the plurality of electrodesS11 to S14, S21 to S24 and S31 to S34 in the display driving mode, andto transfer the touch driving signal generated in the touch integratedcircuit 140 to the plurality of electrodes S11 to S14, S21 to S24 andS31 to S34 in the touch driving mode.

A single electrode 416 acting as the common electrode and the touchelectrode is formed on the second protective layer 414, and a liquidcrystal layer 418 is formed thereon. Here, the electrode 416 acting asthe common electrode and the touch electrode may be one of the pluralityof electrodes S11 to S14, S21 to S24 and S31 to S34 and may have a blockpattern.

An upper substrate 420 having a black matrix 419A and a color filter419B formed thereon is positioned on the liquid crystal layer 418.

Although FIG. 4 illustrates a liquid crystal display device, the presentinvention is not limited thereto and may be applied to various displaydevices that adopt a touch panel.

FIG. 5 is another plan view of a panel included in a display deviceintegrated with a touch screen panel according to an embodiment of thepresent invention.

Referring to FIG. 5, differently from the configuration of FIG. 3,signal lines SL11 to SL14, SL21 to SL24 and SL31 to SL34, which areconnected with the plurality of electrodes S11 to S14, S21 to S24 andS31 to S34 to transfer the touch driving signal or the common voltage,may be formed in the second direction (e.g., lateral direction) in whichthe gate lines GL are formed.

In this case, the touch driving signal generated in the touch integratedcircuit 140 or the common voltage generated or supplied from the commonvoltage supplier may be transferred to all or some of the plurality ofelectrodes S11 to S14, S21 to S24 and S31 to S34 through the signallines SL11 to SL14, SL21 to SL24 and SL31 to SL34 that are formed to beparallel with the gate lines.

Hereinafter, a method for manufacturing the signal lines SL11 to SL14,SL21 to SL24 and SL31 to SL34 (hereinafter, referred to as touch signallines) in FIG. 3 or FIG. 5, which transfer the touch driving signal tothe common electrode as described in FIGS. 1 to 5, and a fabricatingmethod of the present invention, by which the manufacturing process canbe simplified, will be described.

The touch signal lines may be formed in a conductive metal layer M3L (orthe third conductive layer) in the process.

As described above, additional signal lines are required to formelectrodes for providing the common voltage, which are grouped andblocked in the in-cell type, and this may bring about the increase inmasks necessary for the formation of the signal lines. In order toreduce the number of masks, the first electrode (pixel electrode), aconductive metal layer for the touch signal lines and a thin filmtransistor protective layer (planarization layer or overcoat layer)formed on the thin film transistor may be etched at once, and the firstelectrode protective layer (e.g., the second protective layer) and thefirst protective layer may be selectively etched at once. Further, thefirst connection pattern, which connects the first electrode to thesource electrode or the drain electrode of the thin film transistor, maybe made of the same material as the second electrode at the same time asthe second electrode. Now, the process and the structure thereof will bedescribed.

In the present invention, the thin film transistor may be formed on thesubstrate by amorphous silicon (hereinafter, referred to as “a-Si”),metal oxides and poly silicon including low temperature poly silicon(hereinafter, referred to as “LTPS”) and High temperature poly silicon(hereinafter, referred to as “HTPS”), but the present invention is notlimited thereto.

FIG. 6 is a diagram illustrating processes of manufacturing a thin filmtransistor on a substrate.

A reference numeral 610 shows one of the methods for manufacturing thethin film transistor substrate of a-Si, by which the gate electrode andthe activation layer are formed, then the source electrode and the drainelectrode are formed, and then a planarization layer, the firstprotective layer, the pixel electrode, the touch signal line, the secondprotective layer and the common electrode are formed in sequence 615.

A reference numeral 620 illustrates one of the methods for manufacturingthe thin film transistor substrate of metal oxides, by which the gateelectrode, the activation layer, an etching stopper layer and a gatehole (G-hole) are formed, then the source electrode and the drainelectrode are formed, and then the planarization layer, the firstprotective layer, the pixel electrode, the touch signal line, the secondprotective layer and the common electrode are formed in sequence 625.

A reference numeral 630 shows one of the methods for manufacturing thethin film transistor substrate of LTPS, by which a light-shielding (LS)layer, the activation layer, the gate electrode, the contact hole, thesource electrode and the drain electrode are formed, and then the firstprotective layer (or planarization layer), the pixel electrode, thetouch signal line, the second protective layer and the common electrodeare formed in sequence 635.

FIG. 7 is a diagram illustrating examples of processes according to thepresent invention. Processes 615, 625 and 636 of FIG. 6 may be modifiedas shown in FIG. 7.

In an embodiment of the present invention, a single mask (Mask #1) isused for forming the pixel electrode, the touch signal line and theplanarization layer, and another single mask (Mask #2) is used forforming the second protective layer and the first protective layer, asindicated by a reference numeral 790.

Next, another single mask (Mask #3) is used for forming the commonelectrode Vcom or Vdd. As a result, while the processes 615, 625 and 635have five operations, six operations and five operations, respectively,the embodiment of the present invention has three operations only.

The planarization layer of FIG. 7 is an example of the thin filmtransistor protective layer, and the planarization layer may be replacedwith an overcoat layer. The pixel electrode is an example of the firstelectrode, and the second protective layer is an example of the firstelectrode protective layer. Further, the common electrode is an exampleof the second electrode.

As shown in FIG. 7, the common operations with respect to the substratein FIG. 6 may be reduced by using three masks.

FIGS. 8A and 8B are sectional views illustrating configurations of apixel portion, a gate pad portion and a data pad portion of a displaydevice according to an embodiment of the present invention.

All elements of FIG. 8A are the same as those of FIG. 8B except for thesecond connection pattern 850 b.

A gate pad portion 881 and a data pad portion 882 may be made of thesame material and by the same process as those of the thin filmtransistor formed on the pixel portion 883.

Referring to FIG. 8A showing the first embodiment of the presentinvention, a gate electrode 802 is positioned on a substrate 800 in thepixel portion 883 of the display according to an embodiment of thepresent invention. The gate electrode 802 may be formed as doubleelectrodes 802 a and 802 b of a conductive metal layer and a transparentconductive material layer, but the gate electrode is not limited theretoand may be a single electrode or multiple electrodes.

In addition, gate lines 804 a and 804 b are made of the same material asthat of the gate electrode 802 on the substrate 800 in the gate padportion 881.

A gate insulator 810 is formed on the gate electrode 802 and the gateline 804 for the gate pad. Further, an activation layer 812 (or activelayer), a source electrode 824 and a drain electrode 826 are formed onthe gate insulator 810. In addition, data lines 814A and 814B and datalines 816 a and 816 b for the data pad portion 882 are positioned on thegate insulator 810.

The first protective layer 820 and a thin film transistor protectivelayer 830 are accumulated on the source electrode 824, the drainelectrode 826 and the data lines 814A, 814B, 816 a and 816 b insequence. The first protective layer 820 may be omitted and only thethin film transistor protective layer 830 may be accumulated, accordingto the embodiment. The example of the thin film transistor protectivelayer 830 includes the planarization layer or the overcoat layer.

The first electrode 840 a of which the example is the pixel electrode,and the first touch connection pattern 840 b that is made of the samematerial and by the process as those of the first electrode arepositioned on the thin film transistor protective layer 830. Referencenumerals 850 a of FIG. 8A, 850 a and 850 b of FIG. 8B denote conductivemetal layers, and a reference numeral 850 a of FIGS. 8A and 8Bconstitutes the touch signal line. The touch signal line 850 a ispositioned on the first touch connection pattern 840 c and contacts withthe second touch connection pattern 870 b to transfer the touch drivingsignal to the second electrode 870 a.

The second electrode 870 a, of which the example is the commonelectrode, is formed, and the first connection pattern 870 c and thesecond connection pattern 870 b are formed of the same material and bythe same process as those of the second electrode.

The first connection pattern 870 c of FIG. 8A showing the firstembodiment of the present invention connects one of the source electrode824 and the drain electrode 826 with the first electrode 840 a.

The first connection pattern 870 c of FIG. 8B showing the secondembodiment of the present invention is formed on the second connectionpattern 850 b to contact with one of the source electrode 824 and thedrain electrode 826. Further, the second connection pattern 850 b ismade of the same material and by the same process as those of the touchsignal line 850 a on the first electrode 840 a.

The first electrode protective layers 860, 862 and 864 are formed on thefirst electrode 840 a, the first touch connection pattern 840 b, thetouch signal line 850 a and the second connection pattern 850 b, andthey may be the second protective layer as shown in the previousembodiment. The second electrode 870 a and the second touch connectionpattern 870 b on the first electrode protective layer 860, the data padconnection portion 870 d and the gate pad connection portion 870 e areformed. Further, the first connection pattern 870 c is made of the samematerial and by the same process as those of the second electrode 870 aby using the same mask.

The second electrode 870 a may operate as the common electrode in thedisplay driving mode and operate as the touch electrode applied with thetouch driving signal in the touch driving mode.

In addition, the first contact hole 891, the second contact hole 892,the third contact hole 893 and the fourth contact hole 894 are formed inFIGS. 8A and 8B, which will be described later.

The display device of the present invention in FIGS. 8A and 8B will bedescribed in a view of the thin film transistor, hereinafter.

With regard to essential elements constituting the present invention,the gate lines positioned for transferring the gate signals and the datalines for transferring the data signals are positioned in the firstdirection and the second direction, respectively, on the substrate.Also, the thin film transistor is formed at each pixel defined by theintersection of the gate lines and the data lines. The first electrodeis positioned to be spaced from one of the source electrode or the drainelectrode of the thin film transistor, and one example of the firstelectrode may be the pixel electrode as described above. In addition,the second electrode is positioned to face the first electrode, and oneexample of the second electrode may be the common electrode.

As set forth above, when the display device is in the display drivingmode, the second electrode operates as the common electrode that isapplied with the common voltage. Also, when the display device is in thetouch driving mode, the second electrode operates as the touch electrodethat is applied with the touch driving signal.

The first contact hole is formed on the thin film transistor protectivelayer of the thin film transistor. Further, the touch signal line isformed between the first touch connection pattern, which is made of thesame material as that of the first electrode to be separated from thefirst electrode, and the second touch connection pattern, which is madeof the same material of the second electrode to be connected with thesecond electrode. The touch signal line transfers the touch drivingsignal to the second touch connection pattern. Here, the touch signalline may be formed in the conductive metal layer, and may be formed atthe same time as the thin film transistor protective layer by using asingle mask after accumulating the first electrode (pixel electrode), asdescribed later.

The first connection pattern is made of the same material as that of thesecond electrode and connects the first electrode with the sourceelectrode or the drain electrode through the first contact hole.Afterwards, the first protective layer is formed on the first electrodeand the touch signal line.

The second connection pattern 850 b of FIG. 8B showing the secondembodiment of the present invention is made of the same material and bythe same process as those of the touch signal line to be positionedbetween the first connection pattern and the first electrode.

In addition, the second touch connection pattern is positioned on thetouch signal line through the second contact hole formed in the firstprotective layer. At this time, the width of the touch signal line isnarrower than the first touch connection pattern, and the firstelectrode protective layer is positioned at the edge of the width of thetouch signal line. Further, the second contact hole is formed in thefirst electrode protective layer to expose the touch signal line.

In addition, the data pad connection portion and the gate pad connectionportion are made of the same material and by the same process as thoseof the second electrode. More specifically, the data pad connectionportion is positioned through the third contact hole in the firstelectrode protective layer, and the gate pad connection portion ispositioned through the fourth contact hole in the first electrodeprotective layer.

Meanwhile, FIGS. 8A and 8B show the gate pad portion 881 and the datapad portion 882. Now, the display device including the data drivingportion (see 120 of FIG. 1) and the gate driving portion (see 130 ofFIG. 1), which are connected with the gate pad portion 881 and the datapad portion 882, respectively, will be described.

Basically, the display device has N×P thin film transistors, N×p firstelectrodes (e.g., pixel electrodes) connected with the source electrodesor the drain electrodes of the thin film transistors to be spacedtherefrom, and P second electrodes (e.g., common electrodes) facing thefirst electrodes to provide the same signal to N pixels. The moredetailed description will follow below.

The thin film transistor is positioned at each of N×P pixels that aredefined by the intersection of the gate lines, which are positioned inthe first direction on the substrate to transfer the gate signals, andthe data lines, which are positioned in the second direction on thesubstrate to transfer the data signals. Also, the first electrode isspaced from one of the source electrode and the drain electrode of thethin film transistor. Meanwhile, P second electrodes face the firstelectrodes and provide the same signal to N pixels. Further, the thinfilm transistor protective layer (e.g., planarization layer or OC layer)is positioned on the thin film transistor, and the first contact hole isformed in the thin film transistor protective layer. The firstconnection pattern is formed to connect the first electrode with thesource electrode or the drain electrode through the first contact hole.Further, the touch signal line is positioned between the first touchconnection pattern and the second touch connection pattern and transfersthe touch driving signal to the second touch connection pattern. Thefirst touch connection pattern is made of the same material as that ofthe first electrode to be separated from the first electrode.Furthermore, the second touch connection pattern is made of the samematerial as that of the second electrode to be connected with the secondelectrode.

The first connection pattern connects the first electrode with thesource electrode or the drain electrode in the pixel area. Accordingly,the first connection pattern is made of the same material as that of thesecond electrode and connects one of the source electrode and the drainelectrode with the first electrode through the first contact hole. Thefirst connection pattern may exist by the number corresponding to thepixels, that is, N×P first connection pattern may be provided.

In addition, the display device includes the first electrode protectivelayer formed on the first electrode and the touch signal line.

A plurality of the second electrodes may be applied with the touchdriving signal. The touch integrated circuit applies the touch drivingsignal to all or some of the plurality of the second electrodes in thetouch driving mode of the display panel. Further, the data drivingportion supplies the data voltage to a plurality of data lines in thedisplay driving mode, and the gate driving portion sequentially suppliesscan signals to a plurality of gate lines in the display driving mode.

The second connection pattern is positioned between the first connectionpattern and the first electrode and is made of the same material as thatof the touch signal line, as set forth above. Further, the second touchconnection pattern of the display panel is positioned on the touchsignal line through the second contact hole formed in the firstelectrode protective layer. Meanwhile, the width of the touch signalline of the display panel is narrower than the first touch connectionpattern, and the first electrode protective layer is positioned at theedge of the width of the touch signal line. The second contact hole ispositioned in the first electrode protective layer and it can make thetouch signal line exposed, which may be influenced by which is the upperlayer. The data pad connection portion and the gate pad connectionportion of the display device may be made of the same material as thatof the second electrode. The data pad connection portion is positionedthrough the third contact hole in the first electrode protective layerof the display panel, and the gate pad connection portion is positionedthrough the fourth contact hole in the first electrode protective layerof the display panel.

Referring to the second electrode in more detail, the second electrodeacts as the common electrode, which is applied with the common voltage,in the display driving mode of the display device, and acts as the touchelectrode, which is applied with the touch driving signal, in the touchdriving mode of the display device.

FIGS. 9A to 9E are plan views illustrating configurations of a pixelportion, a gate pad portion and a data pad portion of a display deviceaccording to an embodiment of the present invention. In FIGS. 9A to 9E,the thin film transistor protective layer (e.g., planarization layer orovercoat layer), the first electrode protective layer (e.g., the secondprotective layer), the first protective layer and the gate insulator arenot illustrated for the convenience of explanation.

FIGS. 9A, 9B and 9C show plan views of the process of forming the firstembodiment of the present invention in FIG. 8A, and FIGS. 9A, 9D and 9Eshow plan views of the process of forming the second embodiment of thepresent invention in FIG. 8B. Here, FIG. 9A is applied to bothembodiments in common.

Now, the first embodiment of the present invention will be described.

FIG. 9A is a plan view in which the data line, the gate line and thethin film transistor are formed. The data line 816 a for the data padportion, the gate line 804 a for the gate pad portion, the sourceelectrode 824, the drain electrode 826 and the activation layer 812 areformed. The layers of FIG. 9A are accumulated under the first protectivelayer 820 of FIG. 11 as described later.

FIG. 9B is a plan view in which the first electrode 840 a and the firsttouch connection pattern 840 b are made of the same material, and thetouch signal line 850 a is formed on the first touch connection pattern840 a. Further, the first contact hole 891 is formed to allow the firstelectrode 840 a to contact with the source electrode 824. The layers ofFIG. 9B will be shown in FIG. 12E.

FIG. 9C shows that the second electrode 870 a and the first connectionpattern 870 c are made of the same material, and the second touchconnection pattern 870 b, the data pad connection portion 870 d and thegate pad connection portion 870 e are formed of the same material asthat of the second electrode 870 a. The first connection pattern 870 cconnects the first electrode 840 a with the source electrode 824 throughthe first contact hole 891. The accumulation structure thereof will beshown in FIG. 8A.

Now, the second embodiment of the present invention will be described.

After the thin film transistor is formed as shown in FIG. 9A, the firstelectrode 840 a and the first touch connection pattern 840 b are formedof the same material, and the touch signal line 850 a is formed on thefirst touch connection pattern 840 a, as shown in FIG. 9D. In addition,the first contact hole 891 is formed to allow the first electrode 840 ato contact with the source electrode 824. Further, the second connectionpattern 850 b is formed of the same material as that of the touch signalline 850 a to be adjacent to the first contact hole 891 on the firstelectrode 840 a. The accumulation structure of FIG. 9D will be shown inFIG. 14E.

FIG. 9E shows that the second electrode 870 a and the first connectionpattern 870 c are formed of the same material, and the second touchconnection pattern 870 b, the data pad connection portion 870 d and thegate pad connection portion 870 e are formed of the same material asthat of the second electrode 870 a. The first connection pattern 870 cconnects the second connection pattern 850 b formed on the firstelectrode 840 a with the source electrode 824 through the first contacthole 891. The accumulation structure thereof is the same as shown inFIG. 8B.

FIG. 10 illustrates a configuration of a display according to anembodiment of the present invention.

More specifically, in FIG. 10, N×P pixels and thin film transistorsthereof are formed at the crossings of the data lines and the gatelines. Further, P common electrodes exist at the area formed by groupingN pixels. P common electrodes have a pixel area 1010 which shows thepixel where the first touch connection pattern, the second touchconnection pattern and the touch signal line exist. The normal pixelarea 1020 does not have the connection pattern between the touch signalline and the common electrode. The normal pixel area may selectivelyinclude the first connection pattern. Further, the second connectionpattern, and the first connection pattern are made of the same materialas that of the common electrode and the second connection pattern ismade of the same material as that of the touch signal line as describedabove.

Now, the process of forming the first connection pattern 870 a and thesecond connection pattern 850 b in FIGS. 8A and 8B with the decrease inthe number of masks will be described below.

FIG. 11 illustrates accumulation of a thin film transistor, the firstprotective layer, a thin film transistor protective layer and the firstelectrode.

The gate electrode 802 is formed as double electrodes 802 a and 802 b onthe substrate 800, and the gate line 804, which is connected with thegate pad connection portion to which the gate driving portion isconnected, is formed as double electrodes 804 a and 804 b in the sameprocess.

The conductive metal layers 802 a and 804 a may be made of at least oneselected from the group of conductive metal including aluminum (Al),copper (Cu), molybdenum (Mo), chromium (Cr), titanium (Ti),moly-tungsten (MoW), moly-titanium (MoTi) and copper/moly-titanium(Cu/MoTi), but may not be limited thereto. In addition, transparentconductive material layers 802 b and 804 b may be made of one selectedfrom the group including Indium Tin Oxides (ITO), Indium Zinc Oxides(IZO) and carbon nano-tubes (CNT), but may not be limited thereto. Theelectrodes 802 and 804 are not limited to the double electrodes, and maybe formed as a single electrode.

The electrodes 802 and 804 of FIG. 11 may be formed by a single maskduring the formation of the gate lines. In addition, the gate insulator810 may be formed on the electrodes 802 and 804.

The activation layer 812, the source electrode 824 and the drainelectrode 826 are formed on the gate insulator, and at the same time,the data lines 814 and 816 are formed. At this time, a single mask maybe used.

More specifically, the activation layer 812 may be formed of, forexample, semiconductor materials, such as amorphous silicon or polysilicon, such as LTPS, HTPS, or the like. In addition, the activationlayer 812 may be formed of oxide semiconductor materials, such as ZincOxides (ZO), Indium Galium Zinc Oxides (IGZO), Zinc Indium Oxides (ZIO),Ga-doped-ZnO (ZGO), or the like

Further, the source electrode 824 and the drain electrode 826 aresimultaneously formed by using process of forming a thin film, such assputtering or deposition, to thereby complete the thin film transistor.

The first protective layer 820 is formed on the thin film transistor.The first protective layer 820 may be formed of inorganic materials,such as SiO2 and SiNx, or organic materials, such as photo acrylic, butthe present invention is not limited thereto.

In addition, the thin film transistor protective layer 830 is formed onthe first protective layer 820. The planarization layer as an example ofthe thin film transistor protective layer 830 may have tens to hundredsof permittivity and may be made of light rare earth oxides, such asLaAlO3, La2O3, Y2O3 and LaAl3O6, rare earth compound oxides, or bariumstrontium titanate (BST) oxides, but the present invention is notlimited thereto. Further, the thin film transistor protective layer 830may be formed as the overcoat layer by using organic materials.Unevenness between the electrodes may be compensated by the thin filmtransistor protective layer 830, such as the planarization layer or theovercoat layer, to be thereby flattened.

The first electrode layer 840 is formed on the thin film transistorprotective layer 830. The first electrode layer 840 may be made oftransparent conductive materials, such as ITO, IZO and ITZO. The firstelectrode layer 840 provides a function of the pixel electrode throughthe later process and is connected with the source electrode 824 or thedrain electrode 826.

The conductive metal layer 850 for the touch signal line is formed onthe first electrode layer 840. The conductive metal layer 850 is turnedto be the touch signal line 850 a and the second connection pattern 850b through a predetermined etching process.

Photoresist is coated in order to create a photoresist pattern by aphoto lithography process. After that, a mask having a light penetrationarea and a light-shielding area is covered on the photoresist, and thenis exposed to the light to create a desired pattern of the photoresist.The light penetrating the light penetration area makes the photoresisthard and the remaining area is developed, or vice versa.

The fabrication of layers in FIG. 8A according to the first embodimentof the present invention will be described in detail. The beginning ofthe process is shown in FIG. 11 and followed by the process shown inFIGS. 12A to 13E.

FIGS. 12A to 12F illustrate a process of forming the first electrode, atouch signal line and a thin film transistor protective layer accordingto the first embodiment of the present invention.

The process 790 of FIG. 7, by which the first electrode (pixelelectrode), the touch signal line and the thin film transistorprotective layer (planarization layer or overcoat layer) are formed byusing a single mask (Mask #1), will be described with reference to FIGS.12A to 12F.

FIG. 11 shows the beginning of the process.

FIG. 12A shows that photoresist 1210 is coated on the conductive metallayer 850 formed in FIG. 11.

FIG. 12B shows that the conductive metal layer 850 is wet-etched afterthe photoresist is coated, and the first electrode layer 840 iswet-etched to form the first electrode.

FIG. 12C shows that the photoresist is dry-etched to thereby etch thethin film transistor protective layer 830 and the first protective layer820. In this process, the first contact hole 891 is formed through whichthe source electrode 824 is exposed. In the dry-etching of FIG. 12C, thephotoresist 1210 of FIG. 12A is ashed and a portion 1210 a thereofremains.

Referring to the process of FIGS. 12A to 12C, the thin film transistorprotective layer 830 and the first protective layer 820 is dry-etched tocreate a pattern by using the pattern of the first electrode layer 840and the conductive metal layer 850 as a mask.

FIG. 12D shows that the conductive metal layer 850 is etched by usingthe remaining photoresist 1210 a to form the touch signal line 850 a.

In FIG. 12D, the touch signal line 850 a results from the dry-etchingprocess using the photoresist 1210 a.

FIG. 12E shows that the photoresist 1210 a is removed after the touchsignal line 850 a of FIG. 12D is formed.

FIG. 12F shows that one end of the first metal layer 840 of FIG. 12Cprotrudes. Protrusions 1222 and 1223 may result from the process ofetching the thin film transistor protective layer 830 because the firstmetal layer 840 is partially etched. Accordingly, the additionalwet-etching process may be performed with respect to the protrusions1222 and 1223 during the wet-etching of FIG. 12D after the dry-etchingof FIG. 12C or before the wet-etching of FIG. 12D.

Next, the process of forming the second protective layer and the firstprotective layer in the process 790 of FIG. 7 by using a single mask(Mask #2) will be described with reference to FIGS. 13A to 13E.

FIGS. 13A to 13E illustrate a process of forming the first electrodeprotective layer and the second electrode according to the firstembodiment of the present invention.

FIG. 13A shows that the first electrode protective layer 860 is formedon the layer of FIG. 12E and photoresist 1310 is coated thereon. Anexample of the first electrode protective layer 860 may be the secondprotective layer PAS2, but it is not limited thereto.

FIG. 13B shows that the first electrode protective layer 860 on the gatepad portion 881 and the data pad portion 882 is partially dry-etched byashing the photoresist. Layers 862 and 864 are formed at both sides ofthe touch signal line 850 a in the first electrode protective layer.

FIG. 13C shows that the first electrode 840 a and the first touchconnection pattern 840 b are formed by additionally wet-etching thefirst electrode layer 840.

FIG. 13D illustrates that the third contact hole 893 and the fourthcontact hole 894 are formed by dry-etching the layers of FIG. 13C sothat the gate line 804 a for the gate pad portion 891 is exposed throughthe fourth contact hole 894 and the data line 816 a for the data padportion 882 is exposed through the third contact hole 893.

FIG. 13D shows the process of forming the common electrode (the exampleof the second electrode) in the process 790 of FIG. 7 by using a singlemask (Mask #3). As a result, as show in FIG. 8A and FIG. 13E, the secondelectrode 870 a, the first connection pattern 870 c, the second touchconnection pattern 870 b through the second contact hole 892, the datapad connection portion 870 d and the gate pad connection portion 870 eare formed.

The first connection pattern 870 c, which is made of the same materialand by the process as those of the second electrode, contacts the firstelectrode 840 a with the source electrode 824 at the sides thereof.

Five masks may be used in the process from FIG. 11 to FIG. 13E in total.Particularly, since three masks are used in the process of forming thefirst electrode, the second electrode and the touch signal line afterforming the thin film transistor, the process may be simplified.

In the dry-etching process of FIG. 13C, the first electrode 840 a isexposed in the area 1390. The first electrode 840 a may be heat-treatedby selectively conducting an annealing process in order to maintain thesame. That is, the first electrode layer is formed by the amorphousdeposition process, and the first electrode is formed by wet-etching.Then, the first electrode is heat-treated for polymerization in ordernot to be etched in the later process. Accordingly, the first electrodemay be prevented from being etched by accident in other processes.

Now, the process of forming the layers of FIG. 8B according to thesecond embodiment of the present invention will be described in detail.The beginning of the process is shown in FIG. 11 and followed by theprocess shown in FIGS. 14A to 15E.

The process of forming the first electrode (pixel electrode), the touchsignal line and the thin film transistor protective layer (planarizationlayer or overcoat layer) in the process 790 of FIG. 7 by using a singlemask (Mask #1) will be described with reference to FIGS. 14A to 14F.

The first metal layer 840 and the conductive metal layer 850 are formedfirst as shown in FIG. 11, and followed by the later procedures.

FIGS. 14A to 14F illustrate a process of forming the first electrode, atouch signal line, a thin film transistor protective layer according tothe second embodiment of the present invention.

FIG. 14A shows that the photoresist 1410 is coated on the conductivemetal layer 850 formed in FIG. 11. The embodiment of FIG. 14A isdifferent from the first embodiment in that the second connectionpattern 850 b is formed, so the photoresist 1410 thereof is differentfrom the photoresist 1210 of FIG. 12 a.

FIG. 14B shows that the conductive metal layer 850 is wet-etched afterthe photoresist is coated, and the first electrode layer 840 iswet-etched to form the first electrode.

FIG. 14C shows that the photoresist is dry-etched so that the thin filmtransistor protective layer 830 and the first protective layer 820 areetched. In the process, the first contact hole 891 is formed, throughwhich the source electrode 824 is exposed. In the dry-etching of FIG.14C, the photoresist 1410 of FIG. 14A is ashed and a portion 1410 a and1410 b thereof remains.

Referring to the process of FIGS. 14A to 14C, the thin film transistorprotective layer 830 and the first protective layer 820 is dry-etched tocreate a pattern by using the pattern of the first electrode layer 840and the conductive metal layer 850 as a mask.

FIG. 14D shows that the conductive metal layer 850 is etched by usingthe remaining photoresist 1410 a and 1420 b to form the touch signalline 850 a and the second connection pattern 850 b.

In FIG. 14D, the touch signal line 850 a and the second connectionpattern 850 b result from the wet-etching process using the photoresist1410 a and 1410 b.

FIG. 14E shows that the photoresist 1410 a and 1410 b is removed afterthe touch signal line 850 a and the second connection pattern 850 b ofFIG. 14D are formed.

FIG. 14F shows that one end of the first metal layer 840 of FIG. 14Cprotrudes. Protrusions 1422 and 1423 may result from the process ofetching the thin film transistor protective layer 830 because the firstmetal layer 840 is partially etched. Accordingly, the additionalwet-etching process may be performed with respect to the protrusions1422 and 1423 during the wet-etching of FIG. 14D after the dry-etchingof FIG. 14C or before the wet-etching of FIG. 14D.

Next, the process of forming the second protective layer, the firstprotective layer and the second electrode in the process 790 of FIG. 7by using a single mask (Mask #2) will be described with reference toFIGS. 15A to 15E.

FIGS. 15A to 15E illustrate a process of forming the first electrodeprotective layer and the second electrode according to the secondembodiment of the present invention.

FIG. 15A shows that the first electrode protective layer 860 is formedon the layers of FIG. 14E and the photoresist 1510 is coated thereon. Anexample of the first electrode protective layer 860 may be the secondprotective layer PAS2, but it is not limited thereto.

FIG. 15B shows that the first electrode protective layer on the gate padportion 881 and the data pad portion 882 is partially etched by ashingthe photoresist 1510. Layers 862 and 864 are formed at both sides of thetouch signal line 850 a in the first electrode protective layer.

FIG. 15C shows that the first electrode 840 a and the first touchconnection pattern 840 b are formed by additionally wet-etching thefirst electrode layer.

FIG. 15D illustrates that the third contact hole 893 and the fourthcontact hole 894 are formed by dry-etching the layers of FIG. 15C sothat the gate line 804 a for the gate pad portion 891 is exposed throughthe fourth contact hole 894 and the data line 816 a for the data padportion 882 is exposed through the third contact hole 893.

FIG. 15D shows the process of forming the common electrode (the exampleof the second electrode) in the process 790 of FIG. 7 by using a singlemask (Mask #3). As a result, as show in FIG. 8B and FIG. 15E, the secondelectrode 870 a, the first connection pattern 870 c, the second touchconnection pattern 870 b through the second contact hole 892, the datapad connection portion 870 d and the gate pad connection portion 870 eare formed.

Differently from FIG. 8A, the first connection pattern 870 c, which ismade of the same material and by the same process as those of the secondelectrode, contacts the second connection pattern 850 b on the firstelectrode 840 a with the source electrode 824 at the sides thereof.

In the dry-etching process of FIG. 15C, the first electrode 840 a isexposed in the area 1590, and the second connection pattern 850 b isformed on the first electrode 840 a in order to maintain the same.Accordingly, the first electrode may be prevented from being etched byaccident in other processes.

In order to prevent the second connection pattern 850 b of the secondembodiment from being dry-etched, the conductive metal layer may be madeof Mo/Al/Mo, but the present invention is not limited thereto.

As described in the first and second embodiments, in forming the firstelectrode, the touch signal line and the second electrode, the number ofmasks can be reduced to thereby improve productivity and save cost.Although the Vcom-on-top (VOT) structure, by which the second electrodeis formed after the first electrode, is described in the presentspecification, the formation sequence and locations of the firstelectrode and the second electrode may be changeable, and the presentinvention may be applied to the pixel-on-top (POT) structure by whichthe first electrode is formed after the second electrode. The first andsecond embodiments of the present invention may be applied to theVcom-on-top, i.e., common electrode-on-top, structure to which the thinfilm transistor protective layer, for example, the planarization layerPAC or the overcoat (OC) layer are applied. Alternatively, the first andsecond embodiments of the present invention may be applied to thepixel-on-top structure. In addition, the first connection pattern isformed through a side contact when forming the common electrode (thesecond electrode) in the pixel-source-drain (PXL-SD) contact.

In the side contact of the second connection pattern by using a commonelectrode material (Vcom metal) in pixel-source-drain (PXL-S/D) contacthole portion, the conductive metal layer (the third metal layer or M3)constituting the touch signal line may be accumulated on the pixelelectrode.

In the present invention, the thin film transistor protective layer (PACor OC), the second electrode Vcom and the touch signal line (conductivemetal layer, M3) are formed en bloc, so the number of masks may bereduced. Further, in the second connection pattern for connecting thetouch signal line with the first electrode Vcom, the width of the touchsignal line is narrower than the first touch connection pattern, and thefirst electrode protective layer is positioned at the edge of the widthof the touch signal line. Furthermore, the second contact hole ispositioned at the first electrode protective layer to expose the touchsignal line and the second touch connection pattern is connected throughthe second contact hole. There is a feature of the process by which thefirst electrode is wet-etched after the first electrode protective layeris dry-etched. In this case, the first electrode protective layer is notprovided at the area where the second touch connection pattern isformed, and the pattern of the first electrode is retracted inwardduring the wet-etching process for the thin film transistor protectivelayer.

In the application of the first and second embodiments of presentinvention, the thin film transistor protective layer (PAC or OC) and thefirst protective layer (PAS0) may be dry-etched to be a pattern by usingthe pattern (Vcom ITO PTN) of the second electrode as a mask. Further,it is not easy to selectively etch the organic material in thedry-etching of the organic material, so the organic material may bepartially etched or the lower first protective layer (PAS0) may bepartially etched as well. In addition, the thin film transistorprotective layer may be replaced with other organic materials having lowpermittivity and may be applied with a photosensitive material or anon-photosensitive material.

The mask-reduction process of the present invention may be applied tosubstrates including a-Si, Oxides and LTPS, which will be described withreference to FIGS. 18 and 19.

The embodiments of the present invention include the conductive metallayer (M3L) as set forth above.

FIGS. 16 and 17 are flowcharts illustrating a process of forming signallines of a display device in which a touch sensor is built according toan embodiment of the present invention.

FIG. 16 shows the process according to the first embodiment of thepresent invention.

The substrate is prepared (S1610), and the thin film transistor isformed on the substrate (S1620). Then, the thin film transistorprotective layer covering the thin film transistor, the first electrodelayer and the conductive metal layer are accumulated thereon (S1630).Operations S1620 and S1630 have been described in FIG. 11.

Afterwards, as set forth in FIGS. 12A to 12E, the first electrode layer,the conductive metal layer and the thin film transistor protective layerare etched by using the first photo-mask to form the first contact hole,through which the source electrode or the drain electrode is exposed, onthe first electrode layer and the thin film transistor protective layer,and the first electrode and the touch signal line are formed (S1640).

Next, the photoresist is coated by using the second photo-mask after thefirst electrode protective layer is coated, and the first electrode andthe first touch connection pattern separated from the first electrodeare formed (S1650). This process has been described in FIGS. 13A to 13D.After that, the second electrode and the second touch connectionpattern, which is made of the same material as that of the secondelectrode to be connected with the second electrode, are formed by usingthe third photo-mask, and at the same time, the first connectionpattern, which connects one of the exposed source electrode or the drainelectrode with the first electrode through the first contact hole, isformed (S1660). This process has been described above in FIG. 13E.

FIG. 17 shows the process according to the second embodiment of thepresent invention.

The substrate is prepared (S1710), and the thin film transistor isformed on the substrate (S1720). Then, the thin film transistorprotective layer covering the thin film transistor, the first electrodelayer and the conductive metal layer are accumulated thereon (S1730).Operations S1720 and S1730 have been described before in FIG. 11.

Afterwards, as set forth in FIGS. 14A to 14E, the first electrode layer,the conductive metal layer and the thin film transistor protective layerare etched by using the first photo-mask to form the first contact hole,through which the source electrode or the drain electrode is exposed, onthe first electrode layer and the thin film transistor protective layer,and the first electrode, the touch signal line and the second connectionpattern are formed (S1740).

Next, the photoresist is coated by using the second photo-mask after thefirst electrode protective layer is coated, and the first electrode andthe first touch connection pattern separated from the first electrodeare formed (S1750). This process has been described in FIGS. 15A to 15D.After that, the second electrode and the second touch connectionpattern, which is made of the same material as that of the secondelectrode to be connected with the second electrode, are formed by usingthe third photo-mask, and at the same time, the first connectionpattern, which indirectly connects one of the exposed source electrodeor the drain electrode with the first electrode through the firstcontact hole, is formed (S1760). This process has been described beforein FIG. 15E. Indirect connection means that the first connection patternindirectly connects the first electrode with one of the source electrodeand the drain electrode because the second connection pattern is formedon the first electrode and the first connection pattern is formed on thesecond connection pattern.

The data pad connection portion and the gate pad connection portion areformed of the same material and by the same process as those of thesecond electrode in FIGS. 16 and 17. That is, as described in FIGS. 13Eand 15E, the data pad connection portion and the gate pad connectionportion are formed at the same time as the formation of the secondelectrode and the first connection pattern.

Although the process and configuration have been described with respectto the thin film transistor of which the activation layer is amorphoussilicon in the embodiment, the connection pattern between the pixelelectrode and the source/drain electrode of the present invention may beimplemented in the case of a metal oxide semiconductor and poly silicon,such as LTPS. The partial operation 625 of FIG. 7, in which theactivation layer of the thin film transistor is a metal semiconductor,may be applied to process 790 of the present embodiment. Likewise, thepartial operation 635 of FIG. 7 in the case of the LTPS process may beapplied to process 790.

FIG. 18 illustrates an embodiment of the present invention in a casewhere an activation layer of a thin film transistor is a metal oxidesemiconductor.

FIG. 18 shows the connection pattern between the pixel electrode and thesource/drain electrode when applying process 790 of FIG. 7.

A substrate 1800, a gate 1802, a gate insulator 1804, a source electrode1812, a drain electrode 1814, an activation layer 1816, an etchingstopper layer 1818, the first protective layer 1820, a thin filmtransistor protective layer 1822, a pixel electrode 1824 as an exampleof the first electrode, the first electrode protective layer 1826, thefirst touch connection pattern 1890 made of the same material as thefirst electrode, a touch signal line 1830 under the second connectionpattern 1845 made of the same material as the second electrode, and acommon electrode 1840 as the second electrode are formed. Further, thefirst connection pattern 1850 for connecting the pixel electrode 1824and the drain electrode 1814 as the first electrode. The firstconnection pattern 1850 is formed of the same material as that of thesecond electrode 1840 and the second touch connection pattern 1845. Inaddition, the second connection pattern 1895 may be selectively formedunder the first connection pattern 1850, and the second connectionpattern 1895 may be made of the same material as that of the touchsignal line 1830.

FIG. 19 illustrates an embodiment of the present invention in a casewhere an activation layer of a thin film transistor is low temperaturepoly silicon.

FIG. 19 shows the connection pattern between the pixel electrode and thesource/drain electrode when applying the same operation as the process790 of FIG. 7.

In the case of the activation layer of LTPS, a substrate 1900, alight-shielding layer 1902, a buffer layer 1904, a lightly doped drain(LDD) 1906, an activation layer 1908, a gate electrode 1910, a data(source/drain) electrode 1920, a gate insulator 1922, abetween-layer-insulator 1924, a thin film transistor protective layer1926, a touch signal line 1930 for the touch driving signal, a pixelelectrode 1940 as the example of the first electrode, the firstelectrode protective layer 1950, a common electrode 1960 as the exampleof the second electrode, and the first connection pattern 1970 forconnecting the pixel electrode 1940 with the data electrode 1920 areformed. Here, the common electrode 1960 as the second electrode and thefirst connection pattern 1970 are formed of the same material and in thesame process. In addition, the second connection pattern 1990 may beselectively formed of the same material and by the same process as thoseof the touch signal line 1930.

The first touch connection pattern 1931 of the same material as thefirst electrode 1940 is formed under the touch signal line 1930, and thesecond connection pattern 1932 of the same material as the secondelectrode 1960 is formed on the touch signal line 1930.

Although the structure and manufacturing features suggested by theembodiment of the present invention may be applied to the VOT structureincluding the thin film transistor protective layer, such as theplanarization layer or the overcoat layer, the present invention is notlimited thereto, and it may be applied to the POT structure. That is,the mask reduction process of the present invention is compatible withthe pixel-on-top (POT) structure as well as the Vcom-on-top (VOT)structure. In applying the present invention to the POT structure, thefirst electrode, of which the example is the pixel electrode in the VOT(or COT) structure, may be applied to the common electrode, and thesecond electrode, of which the example is the common electrode, may beapplied to the pixel electrode. Further, the pixel electrode and thesource/drain electrode may be connected with each other through a sidecontact during the formation of the common electrode. In the presentembodiment, the thin film transistor protective layer may be replacedwith other organic materials having low permittivity and may be appliedwith the planarization layer including the photosensitive material orthe non-photosensitive material or the overcoat layer made of theorganic material.

The mask-reduction process of the present invention may be applied tothe structure including the touch signal line layer as well as lowersubstrates of a-Si, oxides and LTPS.

The embodiments of the present invention may be applied to the in-celltouch type, but the present invention is not limited thereto. In thefirst embodiment, the first connection pattern for connecting the firstelectrode with the source electrode or the drain electrode through thecontact hole is formed of the same material and by the same process asthose of the second electrode. Further, in the second embodiment, thefirst connection pattern for connecting the first electrode with thesource electrode or the drain electrode through the contact hole and thesecond connection pattern are formed of the same material and by thesame process as those of the second electrode and the touch signal line,respectively. In manufacturing the display device, reduced number ofmasks can be applied to every type of substrates for the connectionpatterns.

While the technical spirit of the present invention has been exemplarilydescribed with reference to the accompanying drawings, it will beunderstood by a person skilled in the art that the present invention maybe varied and modified in various forms without departing from the scopeof the present invention. Accordingly, the embodiments disclosed in thepresent invention are merely to not limit but describe the technicalspirit of the present invention. Further, the scope of the technicalspirit of the present invention is limited by the embodiments. The scopeof the present invention shall be construed on the basis of theaccompanying claims in such a manner that all of the technical ideasincluded within the scope equivalent to the claims belong to the presentinvention.

What is claimed is:
 1. A method for fabricating signal lines of adisplay device integrated with a touch screen panel, the methodcomprising: forming a thin film transistor on a substrate; sequentiallyforming a thin film transistor protective layer covering the thin filmtransistor, a first electrode layer and a conductive metal layer;etching the first electrode layer, the conductive metal layer and thethin film transistor protective layer by using a first photo-mask toform a first contact hole, through which a source electrode or a drainelectrode is exposed, in the first electrode layer and the thin filmtransistor protective layer, and forming a first electrode and a touchsignal line; coating a first electrode protective layer; coatingphotoresist by using a second photo-mask and forming a first electrodeand a first touch connection pattern separated from the first electrode;and forming a second electrode and a second touch connection patternmade of the same material as that of the second electrode to beconnected with the second electrode by using a third photo-mask, and atthe same time, forming a first connection pattern, which connects one ofeither the exposed source electrode or the drain electrode with thefirst electrode through the first contact hole.
 2. The method of claim1, wherein the forming the first electrode and the touch signal linefurther comprises forming a second connection pattern that is made ofthe same material as that of the touch signal line to overlap the firstelectrode.
 3. The method of claim 1, wherein the forming the firstconnection pattern further comprises forming the first connectionpattern on the second connection pattern to indirectly connect the firstelectrode with one of the exposed source electrode or the drainelectrode.
 4. The method of claim 1, wherein the forming the secondtouch connection pattern further comprises forming the second touchconnection pattern on the touch signal line through a second contacthole which is formed in the first electrode protective layer.
 5. Themethod of claim 4, wherein the width of the touch signal line isnarrower than the first touch connection pattern, the first electrodeprotective layer is positioned at an edge of the width of the touchsignal line, and the second contact hole is positioned in the firstelectrode protective layer to expose the touch signal line.
 6. Themethod of claim 1, further comprising: forming a data pad connectionportion with the same material as that of the second electrode to bepositioned through a third contact hole in the first electrodeprotective layer; and forming a gate pad connection portion with thesame material as that of the second electrode to be positioned through afourth contact hole in the first electrode protective layer.